The present invention relates to a dye image receiving material and a method of forming images with said dye image receiving material, particularly to a dye image receiving material used in a heat developable color light-sensitive material or in the thermal image transfer method as well as a method of forming images with said dye image receiving material.
Heat development, in which the developing process is thermally carried out, is known in the art as a means to obtain black-and-white or color images. Also, a heat developable light-sensitive material of so-called transfer type, in which images obtained by heat-developing are transferred from a light-sensitive material to an image receiving layer, is well known.
In general, a heat developable color light-sensitive material has on a support at least one light-sensitive layer containing a binder, light-sensitive silver halide emulsion, dye donating material and reducing agent, and organic silver salts and other photographic additives may be added thereto according to a specific requirement. In a heat developable color light-sensitive material of transfer type, an image receiving material having an image receiving layer capable of receiving dyes is used in combination with the above light-sensitive material.
The present invention particularly relates to an image receiving material preferably used in combination with such a heat developable color light-sensitive material.
The dye image receiving material is conventionally divided into two main groups: one is an image receiving material whose image receiving layer consists of a heat-resistant hydrophobic polymer, and the other is an image receiving material whose image receiving layer consists of a hydrophilic binder containing a dye mordant, as described in Japanese Pat. O.P.I. Pub. Nos. 60643/1985, 119557/1985, 122942/1985, 122940/1985, 122941/1985, etc.
The former utilizes the high dyeing capability of a hydrophobic polymer; therefore, the binder has a dye receptivity in itself. Typical examples of such hydrophobic polymers include polyvinyl chloride described in Japanese Pat. O.P.I. Pub. No. 60643/1985, polyester described in Japanese Pat. O.P.I. Pub. No. 124332/1984 and polycarbonate disclosed in Japanese Pat. O.P.I. Pub. No. 19138/1985. Though these image receiving materials having an image receiving layer composed of such a hydrophobic polymer are high in dye receptivity, they have a drawback, because of the hydrophobic polymer's thermoplasticity, that the image receiving layer is thermally affected to cause a film break in a heat developing process carried out under a high temperature condition, and thereby uneven developing tends to occur. To remove such a drawback, there has been attempted to employ a thermoplastic resin of high heat resistance. This provides an image receiving layer of improved heat resistance, but cannot avoid a lowering of dye receiving capability.
In a dye image receiving material having an image receiving layer composed of a hydrophilic binder containing mordants, a color light-sensitive material is generally composed of a hydrophilic binder. Therefore, a special care is required in peeling a dye image receiving material from a light-sensitive material after heat development. In other words, since heat developing and dye transfer take place in the substantial absence of water, a light-sensitive material and an image receiving material must be closely contacted with each other. This necessitates use of a large amount of suitable thermal solvents. But such a thermal solvent has a tendency to disperse easily into a hydrophilic binder, and when binders of both a light-sensitive material and an image receiving material are composed mainly of a hydrophilic binder, the thermal solvent is liable to hinder clear peeling between the image receiving material and the light-sensitive material after development, causing partial breaks of the light-sensitive layer and the image receiving layer.
In a system using such a light-sensitive material and image receiving material, it is known to carry out heat developing by supplying some quantity of water to a light-sensitive material and/or an image receiving material immediately before heat developing. In this case, the peeling property after heat developing can be improved, as compared with the case using a large quantity of a thermal solvent, by controlling the hardened degree of hydrophilic binders used in both the materials. But this has a drawback of being liable to cause peeling failures when the amount of water is small.
On the other hand, use of a polymer latex in an image receiving layer is already known in the art. Japanese Pat. O.P.I. Pub. No. 156045/1986 discloses addition of a hydrophilic binder, mordant and polymer latex for preventing an image receiving layer from cracking.
In that invention, however, the function of a polymer latex is limited to prevention of layer cracking, and the peeling property between a light-sensitive material and an image receiving material after heat developing is not improved. Further, though Japanese Pat. O.P.I. Pub. No. 245257/1987 discloses application of a polymer latex on a dye mordant layer as a preventive measure against layer cracking, this is also ineffective in solving the above problem like the foregoing prior art.